Numbers of form 5^i*10^j, with i, j >= 0.

Terms

a(0) =1a(1) =5a(2) =10a(3) =25a(4) =50a(5) =100a(6) =125a(7) =250a(8) =500a(9) =625a(10) =1000a(11) =1250a(12) =2500a(13) =3125a(14) =5000a(15) =6250a(16) =10000a(17) =12500a(18) =15625a(19) =25000a(20) =31250a(21) =50000a(22) =62500a(23) =78125a(24) =100000a(25) =125000a(26) =156250a(27) =250000a(28) =312500a(29) =390625